let lis=document.querySelectorAll('span');
		let page01=document.getElementById('page01');
		let page02=document.getElementById('page02');
		let page03=document.getElementById('page03');
		let ltitle1=document.getElementById('ltitle1');
		let ltitle2=document.getElementById('ltitle2');
		let ltitle3=document.getElementById('ltitle3');
		//console.log(lis);
		for(let i=0;i<lis.length;i++){
			lis[i].onclick=function(event){
				if( event.target.classList.contains('first')){
					changePage()
					page01.style.display='block'
					ltitle1.style.borderBottom='orangered 4px solid'
					ltitle2.style.borderBottom='none'
					ltitle3.style.borderBottom='none'
				}else if( event.target.classList.contains('second')){
					changePage()
					page02.style.display='block'
					ltitle2.style.borderBottom='orangered 4px solid'
					ltitle1.style.borderBottom='none'
					ltitle3.style.borderBottom='none'
				}else{
					changePage()
					page03.style.display='block'
					ltitle3.style.borderBottom='orangered 4px solid'
					ltitle1.style.borderBottom='none'
					ltitle2.style.borderBottom='none'	
				}
				
				
			}
			
		}
		
		function changePage(){
			document.querySelectorAll('.page').forEach(el=>{
			el.style.display='none'
			})
			
		}
